1. Field of the Invention
The present invention generally relates to a computer based production dispatch system on the manufacturing shop floor and, more particularly, to a system which automatically interfaces a production dispatch tool to a production planning system to provide an integrated approach to a manufacturing softward design. The invention provides an easy to use, user friendly interface for the shop foreman to dispatch orders in the most efficient way in the event of production stoppage at any point in the manufacturing process. This invention deals with released orders that have to be dispatched, whereas the invention of application Ser. No. 07/127,334 deals with the issue of planning and releasing orders prior to actual release.
2. Description of the Prior Art
The process of designing, developing and manufacturing a new product, or making major changes to existing products, presents many challenges to product managers and manufacturing managers to bring a product to market for the least cost, within schedule while maintaining product quality. In today's highly competitive industries, product managers and manufacturing managers require information to address many problems that arise because of the complexity of new products and the complexity of world-wide production and the changing nature of competition. The requirement that products be manufactured in as short a period as possible while maintaining a low level of inventory on the shop floor to meet customer needs presents conflicting criteria to be analyzed in order to make timely decisions.
Many authors have written books in the field of production management. For example, Joseph Orlicky wrote Material Requirements Planning, published by McGraw-Hill, which has become the industry standard reference for almost all job shop planning requirements. This concept of planning and releasing work to the manufacturing shop floor is well accepted and, even today, many vendors are selling software based on the concept. From a dispatching point of view, this system takes into account only the general concept of a first in, first out (FIFO) basis of dispatching. As mentioned in my copending application Ser. No. 07/127,334, D. T. Phillips and G. L. Hogg published a paper entitled "A State-of-the-Art Survey of Dispatching Rules for Manufacturing Job Shop Operation", International Journal of Production Research, vol. 20, no. 1, (1982) pp. 27-45, which provides varying dispatching rules that can be used in a planning process. IBM Corp. has a product called "Capacity Planning and Operation Sequencing System (CAPOSS)", described in Education Guide No. SR19-5004-0, that provides static dispatching functions in the form of deciding the next operation to be performed for an order after completion of a prior operation. This product provides the capability to change a dispatching process that is pre-assigned to another process. The limitation with this approach is that the system does not analyze the impact of a change to another operation. The system just provides the capability to change the operation and does not analyze the operational dynamics of one order affecting another in the downstream process. What is needed is an expert system that is simple to use and is user friendly to anaylze the dispatch decisions to be made and recommends the alternatives based on a given criteria; e.g., reduce the number of late orders or maximize throughput.
Expert systems are a branch of computer science, generally referred to as artificial intelligence, which exhibits characteristics normally associated with human behavior including learning, reasoning, solving problems and so forth. More specifically, an expert system or "knowledge based" system uses certain rules and a database to provide a user interactive environment in the form of a "consultation dialog", just as the user would interact with a human expert.